Why won’t my laser cut through, when it did last week?

Work the checklist in this order: focus (re-set it; a ramp test settles it), lens (resin haze steals half your power invisibly), air assist (dead pump or kinked line), material batch (plywood glue varies sheet to sheet), and finally belt tension and alignment.

Ninety percent of "my laser got weak" reports resolve at focus or a dirty lens. If all five pass and it still stalls, run a fresh test grid — your true power/speed window may have shifted with the season’s humidity.